Improved dbaw-bbidge



-THoMAs s. sPiniKMAnf, 0F GAMDEN, NEW JERSEY.

Letters Patent No'. 76,542, Jated'Apn'l 7, 1868.

IMPnovBD DRAW-BRIDGE.

.mit rintule refont tu in tigen rttrs ate'nt mit mating mi nftte stmt.

TO ALL WHOM IT- MAY CONCERN:

Be it known that I, THOMAS S. SPEAKMAN, of the city and county of Camden, and State of New Jersey, have invented a new and improved Double Draw-Bridge; and I do hereby declare that the following is a full, clear, and exact description ofthe construction and operation of the same, reference being had to the annexed drawings, (making a. part of this speciicatiom) in which- Figure 1 is a side elevation. 4

Figure 2 is a plan.

In this invention thenbridge is widened atV the draw, and provided with two tracks or waysacr'oss theehannel; so arranged and operating that a vessel passing the bridge cannot for a moment obstruct the travel across it.

In the drawings, A represents the main bridge,.and C thejchannel, by which the vessel B is to pass the bridge. Along both sides of the channel Iexpand or widen the bridge, as shown at D D. Ithen throw con*- necting draw-bridges, G Gacross the ends of the channel, as s een clearly in iig. 2.5 The width of the bridge Y at D D is expanded to'such a degree, that a vessel coming up the stream can pass the lower connecting-bridge G', whilethe u'pper one, G, is shut,iand travel across it is unimpeded, and, after the vessel passes into the spa-ce between the two draws, the lower one cari be closed and the upperA one opened, and, while the vesselis passing the upper. one, travel will cont-inne uninterrupted'across the lower draw.

I would ordinarily employ slide-draws, though any kind may be used 'in connection with a bridge thus constructed. When the slide-drawv is used, its inner -rail,g g', will form a. gate, which, whenthe draw is closed,'will open the way for travel across it, and when the draw -isopen will olose the approachto it, as seen at g', iig.` 2. The space between the two draws must be gradua't'edaccording to the size of the vessels that are liable to pass the bridge. o

A rail, r r, extends along 'the edge of' the bridge, adjacent to the channel, from the rail g to g', to prevent accident.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

A bridge, constructed with the widened parts D D', with the channel C between them, and having twocon necting draws G G', that span the channel, one at the upper and the-other itt-the lower side of the bridge, substantially as and for the purpose specified.

To the above 'specification of' myinvention I have signed my` hand, this 31st day of January, 1868,

I THOMAS S. SPEAKMAN. Witnesses: 4

CHAS. A. Pn'r'rir, SonoN C. KEMON. 

